This invention relates to earth-working vehicles, and more particularly to a vehicle of this description having particular utility in such projects as excavating, road repair, the laying of underground conduit, etc.
Known forms of equipment utilized in performing operations such as those discussed above include what is sometimes referred to as a back hoe taking the form of an articulated boom having a bucket mounted on a tip section of the boom, such back hoe being supported on the end of a vehicle such as a tractor. When equipment of this description is used in a job such as preparing a trench through a paved area, circumstances may arise that would dictate the use of an attachment such as a hydro-hammer, grapple, or compactor, rather than a bucket. This necessitates temporarily halting the excavation job, and the removal of the bucket from the boom with replacement of the bucket with the attachment desired. The procedure is time consuming and unproductive. Equipment is also known which might have, for instance, a back hoe on one end of the vehicle, and a scoop bucket at the other end. However, the position of the operator and the controls that he utilizes in operating the back hoe are not conveniently located for operation of the working implement at the opposite end of the vehicle.
Generally, therefore, it is an object of this invention to provide an improved earth-working vehicle, having markedly improved versatility in performing a job such as an excavation requiring periodically the use of an attachment other than the usual bucket.
A related object to provide such a vehicle where the position of the operator and the controls that he uses is the same, whether using a bucket, or another form of working mechanism.
Following the invention, the operator has good visibility of the area being worked, whether actually excavating the ground with a bucket or loosening up material with a mechanism such as a hydro-hammer.
According to a preferred embodiment of the invention, a vehicle as contemplated herein comprises a frame supported for movement over the ground, as by crawler tracks. Supported on this frame is a rotatable turntable. Mounted adjacent one end of the turntable on the turntable frame, and adjacent one side of the turntable, are a pair of articulated booms, each comprising base and tip sections constrained to movement in vertical parallel planes. Mounted adjacent the same end of the turntable, on the opposite side of the turntable from the boom, are an operator's station and controls. The respective booms may be equipped with different working instrumentalities, such as a bucket, and a hydro-hammer or a compactor.
With the organization described, operator convenience in terms of visibility, and the facility with which a boom may be operated, is substantially the same, irrespective of which boom is being put to use. The booms are prevented from colliding, as they move together with turning movement of the turntable, and are constrained to movement in the parallel planes with respect to the turntable frame.
Weight distribution on the turntable may be essentially the same as where a single boom is provided, since when one boom is not in use, it may be folded back against the turntable and in such a position offers insignificant impairment to weight distribution. Base sections of the booms may be conveniently mounted using a portion of the turntable frame, with enforcement of such frame provided to accommodate mounting of one boom providing the enforcement accommodating mounting of the other.
These and other objects and advantages are attained by the invention, which is described hereinbelow in conjunction with the accompanying drawings, wherein: